I have a problem. The odds are against me. Need help fast.
No, wait … wrong show.
We have an equalizer, and want to use it correctly. I’m sure making a nice pattern with the sliders would be nice, but I’d rather go for optimizing the sound.
The equalizer is an old but stored Audiosource EQ-One II. It has ten sliders for each of two channels, a spectrum analyser (i.e., the coloured lights that respond to different levels), a mic input, and a pink noise generator.
If it makes a difference, here’s the environment it’s in:
Our parlour is roughly ‘D’ shaped. The main rectangle (i.e., not counting the semicircle) is about 30 x 40. The rounded bit has large cut-outs that lead to other rooms (den, dining room, hall, etc.). There are four not-quite-equally spaced bookshelf speakers around the room. The placement of the speakers is a bit limited as the wiring is inside the wall (I could extend the speaker wires, but not sure I could get much better placement). There is also a powered subwoofer, but I don’t believe its placement is important, save that it’s not stuffed in a corner. We’re taking advantage of the receiver’s dual-room capability to drive all four speakers. The main seating is several feet from the walls and faces each other (armchairs). There are hardwood floors, an oriental rug, lots of plants, one of the long walls is all books, and in addition to the two armchairs there is a sofa.
This room is for music only—no video at all, so creating the best two-channel stereo field is all that’s important. The two main benchmarks I’m using listening-wise are DSotM (On the Run), and Unsquare Dance.
So, I assume pink noise out and mic in, but what do I do with the sliders vis-à-vis the pretty lights?
I think you want the pretty lights to be equally tall in each column, and the sliders as high as possible without violating the equally tall condition.
Place the mic at your listening position and adjust the levels on the sliders to boost or diminish frequency bands until you have a nice flat line on the pretty lights.
IAAAudio Engineer
To nitpick, if you’re trying to truly ‘flatten’ the room, you’d need to account for the coloring of the mic. When I tune a room, I use an “RTA Mic”, (Real Time Analyzer) which isn’t necessarily flat, but the processor it’s plugged into knows its characteristics and factors them in. Unless your Equalizer has its own special mic, you won’t be accounting for mic coloring.
This isn’t to imply that I think this is necessary, I’m just being pedantic. I do recommend you use the best mic you can get your hands on. My own home stereo is not carefully tuned in any way.
Audient, if you had the specs for the microphone you were using, could you estimate what shape the “coloured lights” from the Op should be to flatten the room? Or is that placing too much faith in the accuracy of the lights?
i was just thinking about that. I guess it depends on the scale of the lights. If it’s marked in dB, and you had a frequency response graph for the mic, you could manually compensate.
to reiterate, this is entirely over-the-top behavior in my book. I’ve never tried to get this kind of accuracy in a room, in the end, I “EQ to taste” - if I hear something that sounds too bright or dark to my ears, I nudge the corresponding freq on the eq.
And once you are done following the pro advice and have successfully flattened your room, listen to your favorite music and don’t be afraid to tweak it to your own taste. You can put it back to perfectly flat when the guys from the audio magazine come for the article but while it is you who are listening, perfect should mean perfect for you.
After making the pretty lights all line up, smooth the curve a bit so that each slider is reasonably near the next. That is, you don’t want one slider way above or below its neighbors.
IMHO. I’m not an expert, and all my EQ work is done with rock bands.
Tricky part is that the two listening spots (me and Mrs. Devil) are on opposite sides of the long part of the rectangle. Never get things perfect without two equalizers (or a set of sliders per channel) but that’s crazy talk. I just want to get the sound relatively close to theory, then tweak it a bit.
An odd bit to wrap my head around, the EQ is sitting between the source and the receiver. Wouldn’t it make more sense to have it between the receiver and the speakers? Not that there are in/outputs for that, but as it stands, the EQ is good for only one source.
NoCoolUserName – I was standing behind the soundboard at a P-Funk show last week, watching the sound man do his thing. Like playing an instrument it was. Maybe it’s because there are twenty or so of them on stage at once, but it looked extremely complicated and involved.
Ideally, the EQ would go between the pre-amp and amp. They don’t go between the amp and speakers because the EQ would have to be able to output just as much power as the amplifier, making it very expensive.
On a receiver, putting the EQ between the pre-amp and amp can be tricky, as the both are inside the same unit. However, it might be done in a couple of ways depending on the receiver, or perhaps not at all.
Many receivers have a “Tape Loop” which is a set of line level outputs to feed your tape recorder, and a corresponding set of line level inputs to monitor the tape in record or playback mode. You put the EQ in that loop, and select “Tape” as the input. On most receivers, you can select Tape and another input, as they assume you may want to be able to record from any source. So the Tape output feeds the EQ input, which applies it’s frequency response adjustments, then sends its output right back to the receiver. Many EQs had their own Tape Loop and Tape switch built in precisely because you frequently used up the Tape connections on your receiver. So you plug the EQ into the tape connections on the receiver, and plug your tape machine into the tape connections on the EQ.
Some higher end receivers (at least used to) have actual “Pre Out” and “Main In” RCA jacks on the back which shipped with jumpers or small cables connecting them together. For those, you took off the jumper, and again ran the Pre Out to the EQ input, and the output of the EQ right back to the Main In, just like using the Tape Loop, except this way the EQ is always in the signal path, instead of being switched in and out by the Tape switch.
Either of these ways allows the EQ to be in the signal path for all inputs.
However, as EQs seem to have (wrongly, IMHO) largely gone out style for consumer audio, I’m not sure how common these features are on current receivers. It’s been several years since I’ve been out receiver shopping.